Interdigitated leads-over-chip lead frame and device for supporting an integrated circuit die

ABSTRACT

An inventive Leads-Over-Chip (LOC) lead frame includes an assembly of interdigitated leads constructed to overlie double-sided adhesive tape on the front-side surface of an integrated circuit (IC) die. An attachment surface of each lead is adhesively attachable to the tape, and at least some of the leads are constructed to extend across the front-side surface of the die from one edge substantially to another edge, such as an adjacent or opposing edge. As a result, a substantial area of the front-side surface of the die is adhesively attachable to the leads through the tape, so the die is supportable in an IC package in an improved manner, and the heat may be conducted away from the die through the lead frame in an improved manner.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 09/888,885filed Jun. 25, 2001, now U.S. Pat. No. 6,576,987, issued on Jun. 10,2003, which is a continuation of application Ser. No. 08/827,886, filedApr. 7, 1997, now U.S. Pat. No. 6,271,582, issued Aug. 7, 2001.

BACKGROUND OF THE INVENTION

Field of the Invention: The present invention relates to interdigitatedfleads-over-chip lead frames and other devices and methods forsupporting integrated circuit dice.

State of the Art: Integrated circuit (IC) dice or “chips” are small,generally rectangular IC devices cut from a semiconductor wafer, such asa silicon wafer, on which multiple ICs have been fabricated. Bare ICdice are typically packaged to protect them from corrosion by attachingthem to a lead frame for support and heat conduction and then enclosingthem in a die package.

Examples of conventional type lead frames having interdigitized leadframe strips and/or lead fingers thereon are illustrated in U.S. Pat.Nos. 4,949,161 and 5,147,815.

A conventional die package 10, including a type of lead frame referredto as a “Leads-Over-Chip” (LOC) lead frame 12, is shown in a cut-awayview in FIG. 1. The LOC lead frame 12 includes an assembly of conductiveleads 14, each having an underside attachment surface adhesivelyattached to a front-side surface of an IC die 16 using double-sidedadhesive tape 18 so the assembly of conductive leads 14 physicallysupports the IC die 16 within the die package 10. Each conductive lead14 is wire-bonded to one of a multitude of bond pads on the front-sidesurface of the IC die 16, and each conductive lead 14 extends from thedie package 10 to terminate in a pin that may be connected to externalcircuitry (not shown) so circuitry within the IC die 16 may communicatewith the external circuitry through the bond pads and the conductiveleads 14. Of course, while the conductive leads 14 are shown in FIG. 1as being wire-bonded to bond pads extending along a center axis of thefront-side surface of the IC die 16, it will be understood that theleads of an LOC lead frame may also be wire-bonded to bond padsextending about the perimeter of the front-side surface of an IC die.

In another conventional 16 Meg. DRAM semiconductor memory device packagefor NEC Corporation, a die package 210, including a type of lead framereferred to as a “Leads-Over-Chip” (LOC) lead frame 212, is shown in atop view in FIG. 1A. The LOC lead frame 212 includes an assembly ofconductive leads 214, each having an underside attachment surfaceadhesively attached to a front-side surface of an IC die 216 usingdouble-sided adhesive tape (not shown) so the assembly of conductiveleads 214 physically supports the IC die 216 within the die package 210.Each conductive lead 214 is wire-bonded to one of a multitude of bondpads on the front-side surface of the IC die 216, and each conductivelead 214 extends from the die package 210 to terminate in a pin that maybe connected to external circuitry (not shown) so circuitry within theIC die 216 may communicate with the external circuitry through the bondpads and the conductive leads 214. As shown, the conductive leads 214 inFIG. 1A are wire-bonded to bond pads extending along a single side axisof the front-side surface of the IC die 216.

In yet another conventional 4 Meg.×4 DRAM semiconductor memory devicepackage for NEC Corporation, a die package 310, including a type of leadframe referred to as a “Leads-Over-Chip” (LOC) lead frame 312, is shownin a top view in FIG. 1B. The LOC lead frame 312 includes an assembly ofconductive leads 314, each having an underside attachment surfaceadhesively attached to a front-side surface of an IC die 316 usingdouble-sided adhesive tape (not shown) so the assembly of conductiveleads 314 physically supports the IC die 316 within the die package 310.Each conductive lead 314 is wire-bonded to one of a multitude of bondpads on the front-side surface of the IC die 316, and each conductivelead 314 extends from the die package 310 to terminate in a pin that maybe connected to external circuitry (not shown) so circuitry within theIC die 316 may communicate with the external circuitry through the bondpads and the conductive leads 314. As shown, the conductive leads 314 inFIG. 1B are wire-bonded to bond pads extending along both side edges ofthe front-side surface of the IC die 316.

LOC lead frames are well-known in the art, and are described in variousembodiments in U.S. Pat. No. 4,862,245, 5,218,168, 5,250,840, 5,256,598,5,381,036, 5,521,426, and 5,563,443.

Conventional LOC lead frames can sometimes be problematic because thearrangement and design of their leads do not allow the leads to cover anoptimum percentage of the surface area of an IC die when attached to thedie. As a result, the leads are unable to support the die as well asdesired, and the leads do not extract as much heat as desired from thedie.

In yet another type of lead frame configuration, a lead-under-chip typelead frame, illustrated in U.S. Pat. No. 5,360,992, the lead fingersextend under and beyond the semiconductor device, acting as a die paddlefor the device with wire bonds being formed between the bond padslocated on the active surface of the semiconductor device and portionsof the lead fingers extending therebeyond. This type of lead framearrangement requires the use of long lead fingers to extend the lengthof the semiconductor device and therebeyond for wire bonding purposes,thereby affecting the response time of the semiconductor deviceassembly.

In still yet another type of lead frame and integrated circuit package,as illustrated in U.S. Pat. No. 5,585,668, two integrated circuitsemiconductor devices are connected to a common, substantially planar,lead frame, wherein the bond pads on each active surface of asemiconductor device face the common lead frame and are wire bonded tothe lead fingers thereof.

Also, it can be difficult to produce die packages having “mirror image”pin-out arrangements using conventional LOC lead frames. A pair of suchmirror image die packages has one set of die functions (e.g., V_(CC),DQ1, DQ2, WE*, RAS*, A10, A0, A1, A2, and A3) associated with theleft-side pins of a first one of the pair and the right-side pins of asecond one of the pair, and has another set of functions (e.g., V_(SS),DQ4, DQ3, CAS*, OE*, A9, A8, A7, A6, A5, and A4) associated with theright-side pins of the first one of the pair and the left-side pins ofthe second one of the pair. Such mirror image die packages can beuseful, for example, when a pair of die packages is positioned oppositeone another on opposing sides of a Single In-line Memory Module (SIMM)board and shares the same conductors for identical functions. Thedifficulty in producing a pair of mirror image die packages usingconventional LOC lead frames arises because producing the pairtraditionally requires: a pair of mirror image dice and identical LOClead frames, as described in U.S. Pat. Nos. 5,508,565 and 5,530,292;identical dice and a pair of mirror image LOC lead frames, as describedin U.S. Pat. No. 5,508,565; or wire-bonding a central row of bond padson one of the pair of dice to one of an identical pair of LOC leadframes and then reverse-wire-bonding a central row of bond pads on theother of the pair of dice to the other of the pair of LOC lead frames.

Because the traditional methods of producing mirror image die packagesusing mirror image dice and mirror image LOC lead frames require theproduction of an additional part, they are inefficient and expensivemethods. In addition, using only dice with a central row of bond pads tomake mirror image die packages is undesirably restrictive, since manydice have a different arrangement of bond pads.

Therefore, there is a need in the art for a LOC lead frame and otherdevices and methods for supporting IC dice in an improved manner. Such aLOC lead frame should be capable of producing mirror image die packages,if desired, using identical dice having a wide variety of different bondpad arrangements. The lead frame should also conduct heat away from adie in an improved manner.

BRIEF SUMMARY OF THE INVENTION

An inventive integrated circuit (IC) package includes double-sidedadhesive tape overlying and adhesively attached to a front-side surfaceof an IC die. A Leads-Over-Chip (LOC) lead frame in the package includesa plurality of leads overlying the tape and the front-side surface. Anattachment surface of each lead is adhesively attached to the tape, andat least some of the leads extend across the front-side surface of thedie from one edge substantially to another edge. As a result, asubstantial area of the front-side surface is adhesively attached to theleads through the tape, so the die is supported in the IC package in animproved manner, and heat is conducted away from the die in an improvedmanner.

In a further embodiment of the present invention, an electronic systemincludes an input device, an output device, a processor device, and amemory device, and one of the input, output, processor, and memorydevices includes the IC package described above.

In another embodiment, an assembly for supporting an IC die includessupport members, such as LOC lead frame leads, overlying a front-sidesurface of the die. An attachment surface of each support member isadhesively attached to the front-side surface, and at least some of thesupport members extend across the front-side surface from one edgesubstantially to another edge. As a result, a substantial area of thefront-side surface is adhesively attached to the support members.

In a further embodiment, an IC package having a reversible pin-outarrangement includes double-sided adhesive tape overlying and adhesivelyattached to a front-side surface of an IC die. A LOC lead frame issupported by a package housing and includes a plurality ofinterdigitated leads overlying the tape and the front-side surface ofthe die with an attachment surface of each lead adhesively attached tothe tape. Each lead in first and second groups of the leads isconstructed to extend substantially from respective first and secondopposing edges of the front-side surface of the die, across thefront-side surface, over the respective second and first opposing edges,away from the die, and out respective first and second opposing sides ofthe housing to terminate in a pin. Each of a multitude of bond pads onthe front-side surface of the die is alternately coupleable to adjacentfirst and second group leads. As a result, each bond pad is alternatelyaccessible through pins on the first and second opposing sides of thehousing, and the IC package thereby has a reversible pin-outarrangement.

In still another embodiment, an electronic device, such as a SingleIn-line Memory Module (SIMM) board, includes a base, such as a printedcircuit board, a first IC package as described above with a firstpin-out arrangement, and a second IC package as described above with asecond pin-out arrangement that mirrors the first pin-out arrangement.

In a still further embodiment, an IC quad-package having a reversiblepin-out arrangement includes double-sided adhesive tape overlying andadhesively attached to a front-side surface of an IC die. A LOC leadframe is supported by a package housing and includes a plurality ofinterdigitated leads overlying the tape and the front-side surface ofthe die with an attachment surface of each lead adhesively attached tothe tape. Each lead in first, second, third, and fourth groups of theleads is constructed to extend substantially from respective first andsecond adjacent edges and third and fourth adjacent edges of thefront-side surface of the die, across the front-side surface, over therespective second, first, fourth, and third edges, away from the die,and out respective first and second adjacent sides and third and fourthadjacent sides of the housing to terminate in a pin. Each of a firstgroup of bond pads on the front-side surface of the die is alternatelycoupleable to adjacent first and second group leads, and each of asecond group of bond pads on the front-side surface of the die isalternately coupleable to adjacent third and fourth group leads. As aresult, each bond pad in the first group is alternately accessiblethrough pins on the first and second adjacent sides of the housing, eachbond pad in the second group is alternately accessible through pins onthe third and fourth adjacent sides of the housing, and the ICquad-package thereby has a reversible pin-out arrangement.

In still another embodiment, an electronic device, such as a SingleIn-line Memory Module (SIMM) board, includes a base, such as a printedcircuit board, a first IC quad-package as described above with a firstpin-out arrangement, and a second IC quad-package as described abovewith a second pin-out arrangement that mirrors the first pin-outarrangement.

In an additional embodiment, a method for supporting an IC die in an ICpackage includes: positioning the die in proximity to a housing of thepackage; supporting a multitude of support members on the housing; andmaintaining the position of the die in proximity to the housing byadhesively attaching an attachment surface of each support member to afront-side surface of the die and by extending at least some of thesupport members across the front-side surface in adhesive attachmentwith the surface from one edge substantially to another edge so asubstantial area of the surface is adhesively attached to the supportmembers.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is an isometric, cut-away view of a prior art integrated circuit(IC) die package having a Leads-Over-Chip (LOC) lead frame;

FIG. 1A is a top view of a prior art integrated circuit (IC) die packagehaving a Leads-Over-Chip (LOC) lead frame;

FIG. 1B is a top view of a prior art integrated circuit (IC) die packagehaving a Leads-Over-Chip (LOC) lead frame;

FIG. 2 is an isometric, cut-away view of an IC die package having aninterdigitated LOC lead frame in accordance with the present invention;

FIG. 3 is an isometric, cut-away view of an IC die package in accordancewith the present invention having a pin-out arrangement that is themirror-image of a pin-out arrangement of the package of FIG. 2;

FIGS. 4A and 4B are top plan views of the IC die packages of FIGS. 2 and3;

FIG. 5 is an isometric view of a portion of a Single In-line MemoryModule (SIMM) board including the IC die packages of FIGS. 2 and 3;

FIG. 6 is an isometric view of a portion of an IC die quad-packagehaving an interdigitated LOC lead frame in accordance with anotherembodiment of the present invention;

FIG. 7 is an isometric cut-away view of a portion of an IC diequad-package in accordance with the present invention having a pin-outarrangement that is the mirror-image of a pin-out arrangement of thequad-package of FIG. 6;

FIGS. 8A, 8B, and 8C are top plan views of the IC die quad-packages ofFIGS. 6 and 7;

FIG. 9 is an isometric view of a portion of a SIMM board including theIC die quad-packages of FIGS. 6 and 7; and

FIG. 10 is a block diagram of an electronic system including the IC diequad-package of FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

As shown in a cut-away view in FIG. 2, an inventive die package 20includes a Leads-Over-Chip (LOC) lead frame 22 comprising an assembly ofinterdigitated leads 24 supported by a housing 26. A portion of each ofthe leads 24 extends across a front-side surface of an integratedcircuit (IC) die 28 from one edge substantially to another, opposingedge in close proximity to adjacent leads 24 and is adhesively attachedto the front-side surface using double-sided adhesive tape 30 so theleads 24 together support the IC die 28 within the die package 20.Because the leads 24 extend substantially from edge to edge across thefront-side surface of the IC die 28 in close proximity to one another, asubstantial area of the front-side surface (e.g., 30% to 80% or more) isadhesively attached to the leads 24, so the IC die 28 is supported in animproved manner, and heat is conducted away from the IC die 28 throughthe lead frame 22 in an improved manner.

It will be understood by those having skill in the field of thisinvention that while the die package 20 is shown in FIG. 2 in the formof a Thin Small Outline Package (TSOP), the present invention is equallyapplicable to any die package including, for example, a Thin Quad FlatPack (TQFP), a Small Outline J-lead (SOJ) package, a Plastic Leaded ChipCarrier (PLCC), and a Dual In-line Package (DIP). Also, although theleads 24 of the LOC lead frame 22 are shown in FIG. 2 having aparticular shape and a particular arrangement with respect to oneanother, it will be understood that the present invention includeswithin its scope lead frame leads and other support members having anyshape and any arrangement that extend substantially from edge toopposing edge across the front-side surface of an IC die in adhesiveattachment therewith.

Further, it will be understood that the present invention includeswithin its scope any support members extending across an IC die asdescribed, not just support members, such as the leads 24, that serve asconductors for an IC die. Still further, it will be understood that theIC die 28 may comprise any IC die, and that the double-sided adhesivetape 30 may comprise any adhesive tape for attaching the leads 24 to thefront-side surface of the IC die 28. In addition, it will be understoodthat while all the leads 24 are shown in FIG. 2 extending substantiallyfrom edge to edge across the IC die 28, the present invention includeswithin its scope lead frames in which only some of the leads extendsubstantially from edge to edge across an IC die.

Each of the leads 24 is wire-bonded to one of a multitude of bond padson the front-side surface of the IC die 28, and each of the leads 24extends from the die package 20 to terminate in a pin that may beconnected to external circuitry (not shown) so circuitry within the ICdie 28 may communicate with the external circuitry through the bond padsand the leads 24. Thus, for example, one of the leads 24 is wire-bondedat one end to an A0 address bit bond pad on the front-side surface ofthe IC die 28 and extends from the die package 20 to terminate in an A0address bit pin. Of course, while the leads 24 are shown in FIG. 2 asbeing wire-bonded to bond pads extending about the perimeter of thefront-side surface of the IC die 28, it will be understood that thepresent invention includes within its scope leads 24 wire-bonded to bondpads located anywhere on an IC die. It will also be understood that thefunctions (i.e., A0, A1, V_(CC), DQ4, etc.) shown in FIG. 2 associatedwith the die package 20 are illustrative only, and that the scope of thepresent invention is not limited to any particular function set.

As shown in FIG. 3, a die package 40 is identical to the die package 20of FIG. 2, except that the pin-out arrangement of the die package 40mirrors the pin-out arrangement of the die package 20 as a result ofeach of a plurality of interdigitated leads 44 being wire-bonded nearits mid-point to an alternative bond pad on the front-side surface of anIC die 48. As a consequence of this advantageous feature of the presentinvention, identical dice and LOC lead frames can be used to producemirror image die packages. As discussed above, such die packages areadvantageous because they can be placed on opposing sides of a base,such as a printed circuit Single In-line Memory Module (SIMM) board,with their common pins in alignment, thereby simplifying the routing ofsignals to the packages. Such a SIMM board is described below withrespect to FIG. 5.

The mirror image die packages 20 and 40 of FIGS. 2 and 3 are shown intop plan views in FIGS. 4A and 4B, respectively, for clarity.

As shown in FIG. 5, an electronic device 50 includes a portion of abase, such as a SIMM board 52, which includes the mirror image diepackages 20 and 40 of FIGS. 2 and 3 attached to opposite sides of theSIMM board 52 with leads 24 and 44 associated with identical functions(e.g., DQ1, DQ2, and A4) opposing one another. Of course, it will beunderstood that while the functions associated with only some of theleads 24 and 44 are shown in FIG. 5 for clarity, each of the leads 24and 44 typically has a function associated with it (or is ano-connection lead), as described above with respect to FIGS. 2, 3, 4A,and 4B. Because the pin-out arrangements of the die packages 20 and 40are mirror images of one another, the routing of signals common to bothpackages (e.g., DQ1, DQ2, and A4) through circuit traces 54 is simplerthan the routing typically necessary with die packages attached toopposite sides of a SIMM board that are not mirror image die packages.

As shown in FIG. 6 in a view of a portion of a quad-package which is notencapsulated in plastic material to form a completed packaged IC deviceassembly, an inventive die quad-package 60 includes a LOC lead frame 62comprising an assembly of interdigitated leads 64 supported by a housing66. A portion of each of the leads 64 extends across a front-sidesurface of an IC die 68 from one edge substantially to another, adjacentedge in close proximity to adjacent leads 64 and is adhesively attachedto the front-side surface using double-sided adhesive tape 70 so theleads 64 together support the IC die 68 within the die quad-package 60.Because the leads 64 extend substantially from edge to edge across thefront-side surface of the IC die 68 in close proximity to one another, asubstantial area of the front-side surface (e.g., 30% to 80% or more) isadhesively attached to the leads 64, so the IC die 68 is supported in animproved manner, and heat is conducted away from the IC die 68 throughthe LOC lead frame 62 in an improved manner.

It will be understood by those having skill in the field of thisinvention that while the die quad-package 60 is shown in FIG. 6 in theform of a Thin Quad Flat Pack (TQFP), the present invention is equallyapplicable to any die quad-package. Also, although the leads 64 of theLOC lead frame 62 are shown in FIG. 6 having a particular shape and aparticular arrangement with respect to one another, it will beunderstood that the present invention includes within its scope leadframe leads and other support members having any shape and anyarrangement that extend substantially from edge to adjacent edge acrossthe front-side surface of an IC die in adhesive attachment therewith.

Further, it will be understood that the present invention includeswithin its scope any support members extending across an IC die asdescribed, not just support members, such as the leads 64, that serve asconductors for an IC die. Still further, it will be understood that theIC die 68 may comprise any IC die, and that the double-sided adhesivetape 70 may comprise any adhesive tape for attaching the leads 64 to thefront-side surface of the IC die 68. In addition, it will be understoodthat while all the leads 64 are shown in FIG. 6 extending substantiallyfrom edge to edge across the IC die 68, the present invention includeswithin its scope lead frames in which only some of the leads extendsubstantially from edge to edge across an IC die.

Each of the leads 64 is wire-bonded to one of a multitude of bond padson the front-side surface of the IC die 68, and each of the leads 64extends from the die quad-package 60 to terminate in a pin that may beconnected to external circuitry (not shown) so circuitry within the ICdie 68 may communicate with the external circuitry through the bond padsand the leads 64. Thus, for example, one of the leads 64 is wire-bondedat one end to an A0 address bit bond pad on the front-side surface ofthe IC die 68 and extends from the die quad-package 60 to terminate inan A0 address bit pin. Of course, while the leads 64 are shown in FIG. 6as being wire-bonded to bond pads extending about the perimeter of thefront-side surface of the IC die 68, it will be understood that thepresent invention includes within its scope leads 64 wire-bonded to bondpads located anywhere on an IC die. It will also be understood that thefunctions (i.e., A0, A1, V_(CC), DQ4, etc.) shown in FIG. 6 associatedwith the die quad-package 60 are illustrative only, and that the scopeof the present invention is not limited to any particular function set.

As shown in FIG. 7 in a view of a portion of a quad-package IC devicewhich has not been encapsulated in plastic material to form a completedIC device assembly, a die quad-package 80 is identical to the diequad-package 60 of FIG. 6, except that the pin-out arrangement of thedie quad-package 80 mirrors the pin-out arrangement of the diequad-package 60 as a result of each of a plurality of interdigitatedleads 84 being wire-bonded near its mid-point to an alternative bond padon the front-side surface of an IC die 88. As a consequence of thisadvantageous feature of the present invention, identical dice and LOClead frames can be used to produce mirror image die quad-packages. Asdiscussed above, such die quad-packages are advantageous because theycan be placed on opposing sides of a base, such as a printed circuitSingle In-line Memory Module (SIMM) board, with their common pins inalignment, thereby simplifying the routing of signals to thequad-packages. Such a SIMM board is described below with respect to FIG.9.

The mirror image die quad-packages 60 and 80 of FIGS. 6 and 7 are shownin top plan views in FIGS. 8A and 8B, respectively, for clarity. The diequad-package 80 of FIG. 7 is also shown turned clockwise by 90° in a topplan view in FIG. 8C in order to illustrate more clearly the mirrorimage relationship between the die quad-package 60 of FIG. 6 and the diequad-package 80 of FIG. 7.

Although illustrated as mirror image die quad-packages 60 and 80 inFIGS. 6 and 7, it should be understood that alternative arrangementsother than mirror images may be made using the same lead frame designand bond pad configuration for the quad-packages 60 and 80 by attachingthe lead fingers of the lead frame by means of insulating adhesive tapeto the surface of the IC die, for example 68 or 88, selecting thedesired bond pads of the IC die for the desired functions of the IC die,burning out the various fuses associated with non-selected bond pads ofthe IC die to cause such bond pads to be inoperative, and then wirebonding the operative selected bond pads of the IC die to the desiredlead fingers of the lead frame. In this manner, various operativeconfigurations of an IC die and lead frame, other than mirror images,may be obtained using the same IC die and lead frame design.

As shown in FIG. 9, an electronic device 90 includes a portion of abase, such as a SIMM board 92, which includes the mirror image diequad-packages 60 and 80 of FIGS. 6 and 7 attached to opposite sides ofthe SIMM board 92 with leads 64 and 84 associated with identicalfunctions (e.g., V_(CC), A2, and A5) opposing one another. Of course, itwill be understood that while the functions associated with only some ofthe leads 64 and 84 are shown in FIG. 9 for clarity, each of the leads64 and 84 typically has a function associated with it (or is ano-connection lead), as described above with respect to FIGS. 6, 7, 8A,8B, and 8C. Because the pin-out arrangements of the die quad-packages 60and 80 are mirror images of one another, the outing of signals common toboth packages (e.g., V_(CC), A2, and A5) through circuit traces 94 issimpler than the routing typically necessary with die quad-packagesattached to opposite sides of a SIMM board that are not mirror image diequad-packages.

As shown in FIG. 10, the die quad-package 60 of FIG. 6 is incorporatedinto a memory device 100 in an electronic system 102, such as a computersystem, that also includes an input device 104, an output device 106,and a processor device 108. Of course, it will be understood that whilethe die quad-package 60 is shown in FIG. 10 incorporated into the memorydevice 100, it may also be incorporated into any one of the input,output, and processor devices 104, 106, and 108. Also, it will beunderstood that the electronic system 102 may include any one of thepackages 20, 40, and 80 of FIGS. 2, 3, 4A, 4B, 5, 7, 8A, 8B, 8C, and 9instead of, or in addition to, the package 60 of FIG. 6.

Thus, the present invention provides an LOC lead frame and other devicesand methods for supporting IC dice in an improved manner. The inventiveLOC lead frame is capable of producing mirror image die packages, ifdesired, using identical dice having a wide variety of different bondpad arrangements. The inventive lead frame is also capable of conductingheat away from a die in an improved manner.

Although the present invention has been described with reference toparticular embodiments, the invention is not limited to these describedembodiments. Rather, the invention is limited only by the appendedclaims, which include within their scope all equivalent devices ormethods which operate according to the principles of the invention asdescribed.

What is claimed is:
 1. An assembly for use on a printed circuit boardfor use in a computer comprising: an integrated circuit die for use on aprinted circuit board for use in a computer, the integrated circuit diehaving an active surface having a plurality of bond pads thereon, andhaving a first edge and an opposing second edge, at least one bond padof the plurality of bond pads located on the active surface adjacent thefirst edge, and at least one bond pad of the plurality of bond padslocated on the active surface adjacent the opposing second edge, theintegrated circuit die being encapsulated; a piece of tape overlying atleast a portion of the active surface of the integrated circuit die, thepiece of tape adhesively attached to a portion of the active surface ofthe integrated circuit die; and a plurality of leads for use inconnecting the integrated circuit die to circuits of the printed circuitboard for use in the computer, the plurality of leads comprising aplurality of interdigitated leads for overlying a portion of the pieceof tape and adhesively attached to a portion thereof located on aportion of the active surface of the integrated circuit die with a firstportion of the plurality of interdigitated leads extending across atleast a portion of the piece of tape on a portion of the active surfacefrom substantially the first edge of the integrated circuit die tosubstantially the at least one bond pad located adjacent the opposingsecond edge of the integrated circuit die terminating at a location onthe active surface of the integrated circuit die adjacent to and beforethe at least one bond pad adjacent the opposing second edge of theintegrated circuit die and having a second portion of the plurality ofinterdigitated leads extending across the at least a portion of thepiece of tape on the portion of the active surface from substantiallythe opposing second edge of the integrated circuit die to substantiallythe at least one bond pad located adjacent the first edge of theintegrated circuit die terminating at a location on the active surfaceof the integrated circuit die adjacent to and before the at least onebond pad adjacent the first edge of the integrated circuit die, thefirst portion of the plurality of interdigitated leads beinginterdigitated with the second portion of the plurality ofinterdigitated leads, each bond pad of the plurality on the activesurface being for alternative connection using an electrical connectorextending only over a portion of the active surface to adjacent leads ofthe first and second portions of the plurality of interdigitated leads,the first and second portions of the plurality of interdigitated leadseach extending to an edge of the piece of tape proximate to therespective opposing second and first edges of the integrated circuitdie, portions of the plurality of interdigitated leads beingencapsulated.
 2. The assembly of claim 1, wherein at least some of theplurality of interdigitated leads are for extending across the activesurface of the integrated circuit die from the first edge thereofsubstantially to the opposing second edge thereof for adhesivelyattaching at least 80% of an area thereof to the plurality ofinterdigitated leads through the piece of tape.
 3. An assembly having areversible pin-out arrangement for use on a printed circuit board foruse in a computer comprising: an encapsulation material portion having afirst side and an opposing second side; an integrated circuit die havingan active surface with a plurality of bond pads thereon, and having afirst edge and an opposing second edge, at least one bond pad of theplurality of bond pads located adjacent the first edge of the integratedcircuit die and at least one bond pad of the plurality of bond padslocated adjacent the opposing second edge of the integrated circuit die,the integrated circuit die being located in a housing; a piece of tapeoverlying and adhesively attached to at least a portion of the activesurface of the integrated circuit die; and a plurality of leads havingat least portions thereof disposed within the encapsulation materialportion comprising a plurality of interdigitated leads having portionsthereof overlying a portion of the piece of tape and adhesively attachedthereto, each lead of the plurality of interdigitated leads in first andsecond groups of leads extending substantially from the respective firstedge and opposing second edge of the integrated circuit die, at leastone lead of the first group of leads terminating prior to the at leastone bond pad of the plurality of bond pads located adjacent the opposingsecond edge of the integrated circuit die and at least one lead of thesecond group of leads terminating before the at least one bond pad ofthe plurality of bond pads located adjacent the first edge of theintegrated circuit die, across the active surface, over the respectiveopposing second edge and the first edge of the active surface, away fromthe integrated circuit die, and out the respective first and opposingsecond sides of the encapsulation material portion to terminate in apin, each bond pad of the plurality of bond pads on the active surfacebeing alternatively connected by an electrical connection extending overonly the active surface to an adjacent lead of the first and secondgroups of leads for alternately accessing each bond pad through pins ofrespective first and opposing second sides of the housing, each lead ofthe plurality of interdigitated leads in the first and second groups ofthe plurality of interdigitated leads constructed for extendingsubstantially from respective first and opposing second edges of thepiece of tape proximate to the respective first and opposing secondedges of the active surface.
 4. An assembly for use on a printed circuitboard comprising: an integrated circuit die having a front-side surfacehaving a plurality of bond pads thereon, having a first edge, and havingan opposing second edge, at least one bond pad of the plurality of bondpads located on the front-side surface adjacent the first edge, and atleast one bond pad of the plurality of bond pads located on thefront-side surface adjacent the opposing second edge; a piece of tapefor overlying at least a portion of the front-side surface of theintegrated circuit die and adhesively attached to a portion thereof; anda plurality of leads having portions thereof encapsulated comprising aplurality of interdigitated leads for overlying at least a portion ofthe piece of tape and at least a portion of the front-side surface ofthe integrated circuit die being adhesively attached thereto, a firstportion of the plurality of interdigitated leads extending across thefront-side surface of the integrated circuit die from the first edgethereof substantially to the opposing second edge thereof terminating onthe front-side surface of the integrated circuit die before the at leastone bond pad of the plurality of bond pads located adjacent the firstedge of the integrated circuit die and a second portion of the pluralityof interdigitated leads extending across the front-side surface of theintegrated circuit die from the opposing second edge thereofsubstantially to the first edge thereof terminating on the front-sidesurface of the integrated circuit die before the at least one bond padof the plurality located adjacent the opposing second edge, the firstportion of the, plurality of interdigitated leads being interdigitatedwith the second portion of the plurality of interdigitated leads andeach bond pad on the front-side surface being for alternative connectionusing an electrical wire connection extending only over the front-sidesurface to adjacent leads of the first and second portions of theplurality of interdigitated leads, the first portion of the plurality ofinterdigitated leads extending across the front-side surface of theintegrated circuit die from the first edge thereof substantially to theopposing second edge thereof for extending to an edge of the piece oftape proximate to the opposing second edge of the integrated circuitdie.
 5. The assembly of claim 4, wherein at least some of the pluralityof interdigitated leads are for extending across the front-side surfaceof the integrated circuit die from the first edge thereof substantiallyto the opposing second edge thereof to couple to one of the plurality ofbond pads.
 6. The assembly of claim 4, wherein at least some of theplurality of interdigitated leads are for extending across thefront-side surface of the integrated circuit die from the first edgethereof substantially to another, adjacent edge thereof to couple to oneof the plurality of bond pads.
 7. An assembly having a reversiblepin-out arrangement for use on a printed circuit board for use in acomputer comprising: a housing having a first side and an opposingsecond side formed by encapsulation, the housing forming a portion of anintegrated circuit package; an integrated circuit die located in theintegrated circuit package, the integrated circuit die having afront-side surface with a plurality of bond pads thereon and having afirst edge and an opposing second edge, at least one bond pad of theplurality of bond pads on the front-side surface located adjacent thefirst edge and at least one bond pad of the plurality of bond pads onthe front-side surface located adjacent the opposing second edge, theintegrated circuit die located within the housing; a double sidedadhesive piece of tape overlying a portion of the front-side surface ofthe integrated circuit die and adhesively attached thereto; and at leasta portion of a lead frame supportable by the housing having portionsthereof located in the housing forming portions of the integratedcircuit package, the lead frame including a plurality of interdigitatedleads overlying and adhesively attached to at least a portion of thepiece of tape and portions of the front-side surface of the integratedcircuit die, each lead in first and second groups of leads of theplurality of interdigitated leads extending substantially from therespective first edge and opposing second edge of the integrated circuitdie and having an end thereof terminating before the at least one bondpad of the plurality of bond pads located adjacent one of the first edgeand the opposing second edge of the integrated circuit die, extendingover the respective opposing second edge and the first edge of thefront-side surface of the integrated circuit die, extending away fromthe integrated circuit die, and extending out the respective first sideand opposing second side of the housing to terminate in a pin, at leasttwo bond pads of the plurality of bond pads on the front-side surfacebeing alternately connected to adjacent leads of the first and secondgroups of leads of the plurality of interdigitated leads via anelectrical connection extending across only portions of the front-sidesurface to the plurality of interdigitated leads extending across thefront-side surface of the integrated circuit die and accessible throughpins on the first and opposing second sides of the housing, each lead inthe first and second groups of the leads of the plurality ofinterdigitated leads constructed for extending substantially fromrespective first and second edges of the piece of tape proximate to therespective first and opposing second edges of the integrated circuitdie.